ScienceDaily: Drought periods followed by rainfall caused nitrate levels to increase to the highest ever measured in some Midwest streams during a 2013 study, according to a U.S. Geological Survey report published today in the Journal of Environmental Quality.
Nitrate, a form of nitrogen, is a common pollutant in U.S. streams and groundwater. Excessive concentrations in streams and lakes can adversely affect biological communities and spur algal growth, which can lead to harmful algal blooms and deplete oxygen...